New Bioconjugated Technetium and Rhenium Folates Synthesized by Transmetallation Reaction with Zinc Derivatives.

The zinc dithiocarbamates functionalized with folic acid and were synthesized with a simple straightforward method, using an appropriated folic acid derivative and a functionalized zinc dithiocarbamate (). Zinc complexes and show very low solubilities in water, making them useful for preparing Tc-99m radiopharmaceuticals with a potentially high molar activity. Thus, the transmetallation reaction in water medium between the zinc complexes or and the cation -[Tc(HO)(CO)], in the presence of the monodentate ligand TPPTS, leads to the formation of the 2 + 1 complexes -[Tc(CO)(SS)(P)] bioconjugated to folic acid ( and ).

Bioconjugated technetium carbonyls by transmetalation reaction with zinc derivatives.

The transmetalation reaction between zinc dithiocarbamates functionalized with organic groups and the cation fac-[Tc(HO)(CO)] has been studied as a new strategy to bind biomolecules to this radionuclide for preparing radiopharmaceuticals with high molar activity. All complexes were obtained in high yields by heating at moderate temperatures and without subsequent purification. The chemical identity was ascertained by HPLC comparison with the homologous rhenium complexes.

Direct Synthesis of Rhenium and Technetium-99m Metallosurfactants by a Transmetallation Reaction of Lipophilic Groups: Potential Applications in the Radiolabeling of Liposomes.

A new zinc dithiocarbamate functionalized with palmitoyl groups is described as a useful tool for the preparation of metallosurfactants through a transmetallation reaction with the transition metals rhenium and technetium. An amphiphilic rhenium complex is synthesized by a transmetallation reaction with the zinc complex in presence of the polar phosphine sodium triphenylphosphine trisulfonate, which leads to a rhenium complex with a lipophilic dithiocarbamate and a polar phosphine ligand. The study of this rhenium complex has shown that it self-aggregates, leading to the formation of aggregates that have been analyzed by dynamic light scattering and cryotransmission electron microscopy (cryo-TEM).

Metallosomes for biomedical applications by mixing molybdenum carbonyl metallosurfactants and phospholipids.

New supramolecular systems have been prepared by mixing molybdenum organometallic metallosurfactants M(CO)5L and M(CO)4L2 {L = Ph2P(CH2)6SO3Na} with the phospholipid phosphatidylcholine. The analysis of the resulting supramolecular structures using dynamic light scattering and cryo-transmission electron microscopy has shown the formation of different aggregates depending on the metallosurfactant/phospholipid ratio, as well as a significantly different behaviour between the two studied metallosurfactants. Mixed vesicles, with properties very similar to liposomes, can be obtained with both compounds, and are called metallosomes.

Low-toxicity metallosomes for biomedical applications by self-assembly of organometallic metallosurfactants and phospholipids.

A new and convenient strategy for the preparation of metallosomes has been developed by mixing organometallic metallosurfactants and phospholipids. These aggregates show the characteristic properties of liposomes (stability upon dilution and low toxicity) and the toxicity is at least ten-fold lower than that of the metallosurfactant aggregates without phospholipids.